An onClipEvent detects when the mouse button is pressed, and sets a variable called draw to a value of “true”. Then it assigns the x and y positions of the mouse cursor to variables.
Let’s look at the Flash Drawing API; it lets you draw dynamically in a published SWF. The API can draw either lines or curves, and you can connect those lines and curves to create rectangles or ovals. To break down the drawing API commands that we’ve used here:
_root.drawing.lineStyle(_root.base.bsize, _root.currentcolor, _root.base.opac) ;
Remember that empty movie clip? We’re drawing inside that clip, and using lineStyle to set the attributes. The parameters of lineStyle are the size of the line, the color, and the opacity, which can be entered either as values or as variables.
_root.drawing.moveTo(_root._xmouse, _root._ymouse) ;
This moves the movie clip “drawing” to the same x and y position of the mouse using moveTo. It does exactly what it says, with its only parameters being an x and y coordinate. This is the starting point of the line.
Next an if statement checks to make sure that the brush is the active tool and the help file isn’t visible, and then does the following:
_root.drawing.lineTo (_root._xmouse-1,_root._ymouse-1) ;
lineTo draws a line from the starting point defined in moveTo to the coordinates defined by lineTo’s parameters. In this case all I’ve done is create a one-pixel line so that users can “speckle” draw even if the mouse cursor isn’t moved.
